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Biomedical subjects

G M von Reutern

Publications and source records attributed to G M von Reutern.

At least 19 recordsLinked to original sources
PubMed2002

[Treatment of ischemic stroke in 14 neurologic stroke units. An evaluation of the stroke databank of the German Stroke Aid Foundation].

This study compares the treatment characteristics of 3,740 patients with acute ischemic stroke in 14 established German stroke units. Follow-up after 3 months in surviving patients additionally assessed functional outcome and risk factor modification. The median age was 68 years and 41.9% were women. Twenty-six percent of all patients were admitted within 3 h after the event, and 4.2% received systemic thrombolysis. The median length of stay of all patients in the stroke unit was 3 days. Thereafter, 63% were transferred to another ward in the documenting clinic. The mean length of stay in the documenting hospital was 12 days. In seven hospitals with a follow-up rate of > 80%, mortality amounted to 10.5%, and 56.2% of the patients regained functional independence. This study demonstrates the relatively favorable prognosis of patients in German stroke units as well as the low standardization of diagnostic work-up and treatment strategies.

Aged↗
PubMed1999

[Stroke treatment with stroke unit and rehabilitation by a team. A model for a staged management].

This is a report of an interdisciplinary approach to diagnosis and treatment of stroke, combining a stroke unit and rehabilitation in one clinic. This series contains unselected patients from a narrow surrounding. Mean age of 559 patients was 68.7 years (median 70 years). 25% of patients had an initial Barthel index of < 30, 20% presented with TIA's and PRIND's. 9% suffered from cerebral hemorrhage. The unbroken chain of care allowed a relative short length of stay in the acute care (9.4 days) without prolonging the rehabilitation phase. The one month mortality was 6.7%, one year mortality 18.3%. Discharge to a nursing home was necessary in 5.4%. Overall more than 90% of our patients have been treated continuously in our clinic. Combining modern diagnostics with early onset rehabilitation seem advantageous.

Aged↗
PubMed1999

[Color duplex ultrasonography of the intracranial vertebro-basilar system: improved imaging by echo signal enhancement].

PURPOSE: Transcranial colour-coded duplex sonography allows differentiation of both vertebral arteries and the proximal basilar artery by transoccipital insonation. However, imaging is often incomplete. Therefore the aim of this study was to show to what extent imaging of vertebrobasilar arteries can be improved with the use of the echosignal enhancing agent Levovist (LV) in normal subjects without vascular abnormalities or occlusive disease. METHODS: In 30 subjects extracranial Doppler and duplex sonography has been used to exclude hypoplasia and proximal or distal obstructions of the vertebral arteries. The intracranial vertebral arteries and the basilar artery were then examined before and after fractionated injection of LV (300 mg/ml, 4 g) by means of colour-coded transoccipital duplex sonography including videorecording. RESULTS: Without LV only 17 of 90 possible segments could be imaged completely (basilar artery and both vertebral arteries in 30 subjects). After LV 72 of 90 possible segments could be demonstrated. The confluence of the vertebral arteries could be localised in 22 of 30 subjects by means of LV. The average depth was 6.7 cm (5.5 to 8 cm). Additionally branches of the main arterial trunks could be imaged. The basilar artery could be followed up to a depth of 10 cm. In most cases the distal part of the basilar artery could not be evaluated not even by means of LV enhancement. CONCLUSIONS: Imaging of the vertebrobasilar arteries including the proximal basilar artery could be definitely improved by means of echosignal enhancing Levovist. Imaging of the distal basilar artery was not satisfactory. The confluence of the vertebral arteries could not be precisely localised in all cases due to the course of the arteries.

Adult↗
PubMed1998

Consensus opinion on diagnosis of cerebral circulatory arrest using Doppler-sonography: Task Force Group on cerebral death of the Neurosonology Research Group of the World Federation of Neurology.

BACKGROUND AND PURPOSE: Oscillating flow or systolic spikes are typical Doppler-sonographic flow signals found in the presence of cerebral circulatory arrest, which if irreversible, results in brain death. The Neurosonology Research Group (NSRG) of the World Federation of Neurology (WFN) created a Task Force Group in order to evaluate the role of Doppler-sonography as a confirmatory test for determining brain death. METHODS: The available evidence from the literature has been reviewed and discussed by a group of experts, the members of the Task Force Group on cerebral death of the NSRG. RESULTS AND CONCLUSIONS: Extra- and intracranial Doppler-sonography is a useful confirmatory test to establish irreversibility of cerebral circulatory arrest as optional part of a brain death protocol. Doppler-sonography is of special value when the therapeutic use of sedative drugs renders electroencephalography unreliable. Doppler-sonographic criteria are defined and guidelines for the use of Doppler-sonography in this setting are presented.

Blood Flow Velocity↗
PubMed1998

[Diagnosis of cerebral circulatory arrest with Doppler sonography. Results of a survey].

In 1991 the diagnosis of cerebral circulatory arrest with Doppler sonography was accepted by the Medical Council of the Bundesaerztekammer as one of the methods able to shorten the waiting time for fulfilling the criteria for diagnosis of cerebral death. A survey was undertaken to determine how frequently Doppler sonography has been used since that time in certifying brain death. A total of 400 questionnaires were sent out to all neurological (272) and neurosurgical (128) departments in Germany. In all, 226 questionnaires were returned. In 71 departments, Doppler sonography has been used to certify brain death, mostly combined with other methods. The question of whether false positive results have been observed was answered five times in the affirmative. The background to these cases was clarified by telephone calls. In order to indicate pitfalls, the examiners reported borderline situations which in part did not fulfil the prerequisites. In none of these cases had the diagnosis of brain death been based on ultrasound data. Doppler sonography for the diagnosis of cerebral circulatory arrest has been used by a considerable number of neurological and neurosurgical departments in Germany as an additional confirmatory test and rather seldom as the only method to shorten the waiting period.

Brain↗
PubMed1993

[Color-coded duplex ultrasound in pre-occlusive stenoses of the internal carotid artery].

In a prospective study the results of 238 consecutive ultrasound examinations of the carotid artery were correlated with angiography to test the reliability of colour coded duplex sonography in preocclusive carotid artery disease. This series was compared with a series of 611 vessels with angiographically controlled conventional duplex sonography. In 61 resp. 84 cases stenoses > or = 90% or occlusions of the internal carotid artery were found. The reliability of colour coded duplex sonography for the diagnosis of > or = 90% stenoses was extremely high (sensitivity and specificity 98%), as well as in preocclusive, > 95% stenoses (100% and 98%), and for the diagnosis of occlusion, after exclusion of angiographic false positive diagnosis of occlusion (95% and 99%). Statistically colour coded flow imaging failed to increase significantly the high diagnostic sensitivity or specificity of conventional duplex sonography, especially in preocclusive carotid artery disease. However, the remarkable increase in frequency of the diagnosis preocclusive stenosis with the introduction of colour coded Duplex Sonography probably reflects a higher sensitivity of this method. In addition the direct comparison of both ultrasound techniques showed a better image of the vessel wall abnormalities and the residual lumen with colour coded duplex sonography.

Blood Flow Velocity↗
PubMed1992

[Spontaneous regression of significant stenoses and occlusions of the internal carotid artery].

19 patients with severe stenoses or occlusions of the internal carotid artery showed spontaneous recanalization at follow-up. The cause of the stenotic process was spontaneous or traumatic dissection, fibromuscular dysplasia, ergotism or arteriosclerotic disease. Total recanalization occurred in carotid artery dissections coinciding with the best clinical outcome. In fibromuscular dysplasia and arteriosclerotic process, recanalization was seldom found, incomplete, and the clinical course was less favourable.

Adult↗
PubMed1991

[Acute circulatory disorders of the eye. Clinical findings and results of Doppler sonography of the internal carotid artery].

Clinical and Doppler sonographic findings on the internal carotid artery of 218 patients with acute central retinal artery obstruction (42), branch retinal artery obstruction (43), anterior ischemic optic neuropathy (AION) (51), amaurosis fugax (AF) (21), and retinal vein occlusions (61) were evaluated. The most prominent finding was that only 1 out of 51 patients with AION and none of 61 patients with retinal vein occlusions showed a relevant stenosis or occlusion of the internal carotid artery. In contrast, however, patients with acute central retinal artery obstruction and branch retinal artery obstruction and those with AF revealed stenoses or occlusions of the internal carotid artery in approximative one-third to one-fourth of the cases. No excavation of the optic disc (cup) occurred in patients' eyes affected by AION or in the other eye. Fourteen of 51 patients with AION showed a "stuttering progression" of their visual function. The patients with progressive loss of vision were significantly younger on average than patients with permanent visual loss due to AION. Some of these cases with progressive field defects revealed an increase in edema of the optic discs and in hemorrhages. Patients with acute central retinal artery obstruction showed very high blood pressure values more often than patients with AION. Retinal emboli (Holenhorst plaques) were very often seen in patients with branch retinal artery obstruction (in 29 of 43 patients; 67%). However, they rarely occurred in patients with acute central retinal artery obstruction (5 of 42 patients). Only 1 of 51 cases with AION showed retinal emboli.

Adult↗
PubMed1991

[Terminology of ultrasound vascular diagnosis].

There is at present no accepted nomenclature regarding diagnostic vascular ultrasound. At two scientific meetings, the Study Group for Vascular Diagnosis of the German Society of Ultrasound in Medicine (DEGUM) developed a terminology for Doppler and duplex sonography of the arteries and veins supplying the brain and of peripheral vessels. The most important of these sonographic terms and their synonyms are presented. Recommendations as to which of the presently employed terms should be avoided, are given.

Blood Flow Velocity↗
PubMed1990

[Terminology of ultrasonic vascular diagnosis].

There is at present no accepted nomenclature regarding diagnostic vascular ultrasound. At two scientific meetings, the Study Group for Vascular Diagnosis of the German Society of Ultrasound in Medicine (DEGUM) developed a terminology for Doppler and duplex sonography of the arteries and veins supplying the brain and of peripheral vessels. The most important of these sonographic terms and their synonyms are presented. Recommendations as to which of the presently employed terms should be avoided, are given.

Brain↗
PubMed1990

Ischemic stroke due to protein C deficiency.

Plasma protein C exerts anticoagulatory effects by inactivating factors V and VIII. Hereditary protein C deficiency is transmitted as an autosomal dominant disorder. Homozygous individuals usually develop purpura fulminans as newborns; heterozygous protein C-deficient individuals are at increased risk for venous thrombosis and pulmonary embolism. However, arterial thrombosis has been only rarely observed. We describe a young patient with heterozygous protein C deficiency who experienced a severe stroke due to thrombotic occlusion of the left middle cerebral artery.

Adult↗
PubMed1989

Hemodynamic effects of innominate artery occlusive disease. Evaluation by Doppler ultrasound.

Between 1976 and 1987 we saw 20 patients presenting with stenosis or occlusion of the innominate artery with a measurable hemodynamic effect. This corresponds to less than 0.1% of our patients subjected to noninvasive vascular testing. The hemodynamic sequelae involved the vertebral as well as the carotid arteries. The majority of the cases (n = 17) showed a vertebral steal and only minor concomitant alterations of carotid artery flow. Only three patients had a carotid steal in addition to the vertebral steal. In general, the vertebral steal is predominant over the carotid steal and precedes the latter. We propose a phenomenological classification of innominate artery disease following the severity of hemodynamic changes. Type I shows systolic deceleration or alternating flow in the right vertebral artery and only minor changes in the carotid arteries. Type II is characterized by reversed flow in the ipsilateral vertebral artery and systolic deceleration in the carotid arteries and type III by alternating flow or even complete steal in the carotid arteries in addition to vertebral artery steal. Continuous wave Doppler ultrasound is a valuable noninvasive method for examinating innominate artery occlusive disease and its hemodynamic sequelae. In special cases the additional use of duplex- and transcranial sonography is useful.

Adult↗
PubMed1989

Spatial resolution of transcranial pulsed Doppler technique in vitro evaluation of the sensitivity distribution of the sample volume.

The spatial resolution of pulsed Doppler sonography is determined by the size of the sample volume. It is known that the axial length is dependent upon the duration of the range gate interval and the lateral extension upon the beam width. In addition, the working size is also a function of the sensitivity distribution within the sample volume. All of these parameters determine the working size of the sample volume. Especially for the transcranial Doppler evaluation of the basal cerebral arteries, the site and the working size of the sample volume are essential diagnostic criteria. To measure the working size of the sample volume a flow rig with a thin tube target has been developed and used. The highest sensitivity (100% level) was registered only in a relatively small area and only if the center of the sample volume hit the target. At the 10% level the size of the sample volume increased 5 to 10 times in the lateral and axial dimension in comparison with the 90% level. Therefore, the Doppler signal from a strong reflector distant from the center of the sample volume may mask the signal of a weak reflector located within the center. This lack of spatial resolution due to sensitivity effects may result in clinical misinterpretation. The manufacturers should be urged to supply more precise information relative to the sample volume size.

Blood Flow Velocity↗
PubMed1988

Transcranial Doppler ultrasonography during cardiopulmonary bypass in patients with severe carotid stenosis or occlusion.

Blood flow velocity of the middle cerebral artery was monitored during cardiopulmonary bypass procedures by means of transcranial Doppler ultrasonography. Our investigation was carried out in a group of 16 patients with severe carotid stenosis or occlusion and in a control group of 42 patients with no or stenosis of less than 50% local diameter reduction. After onset of cardiopulmonary bypass, both groups showed a short unstable phase followed by increased blood flow velocity (10% increase ipsilateral to the obstruction, 27% increase in the control group). Just before rewarming, blood flow velocity was still comparable to (control group -3%) or higher than (ipsilateral to obstructions +14%) prebypass values. Analysis of three patients with postoperative diffuse encephalopathy did not reveal reduced blood flow during cardiopulmonary bypass as a relevant factor. Two of the three showed luxury perfusion. Reduced perfusion due to carotid obstruction was not observed during cardiopulmonary bypass and therefore cannot be considered a significant risk factor for the development of intraoperative stroke.

Adult↗
PubMed1988

[Surgical indications in asymptomatic internal carotid artery stenosis and in relation to heart surgery interventions].

In the last 30 years, carotid endarterectomy has been employed on a wide-spread basis with the intention of providing surgical prophylaxis of stroke. Currently, however, there is no evidence available from prospective, randomized comparative studies indicating a clear superiority of surgical treatment versus medical treatment with respect to stroke prophylaxis or improvement in survival. Based on recent publications with sufficiently large patient populations, operative mortality appears to be about 1% and the rate of perioperative stroke about 3.4%. In those with symptomatic internal carotid stenosis, without surgery there is a 5% yearly risk of cerebral infarction such that carotid endarterectomy possibly appears warranted. In contrast, in association with asymptomatic internal carotid stenosis, that is, in the absence of any symptoms indicative of cerebral hypoperfusion, based on several recent prospective studies, the yearly rate of cerebral infarction is 1 to 2% and, consequently, less than that of the prophylactic surgical intervention. Additionally, carotid endarterectomy does not render complete protection against stroke and the follow-up curves for the respective treatments do not differ meaningfully, even during longterm observation. Accordingly, for asymptomatic internal carotid stenosis, the indication for surgery has not been clearly established. Among those with asymptomatic carotid stenosis, there may be a subgroup of individuals with high-grade luminal obstruction or multiple vessel disease, who according to several studies, appear to be at a higher risk of subsequent complications even though this has not yet been confirmed by prospective, randomized studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Artery Diseases↗